SurveyUSA is a strongly rated pollster. It includes cellphones in its sample, which made a fair amount of difference in this poll; Mr. Obama trailed by six points among land-line households. And it gives its respondents the option of completing the interview in Spanish.

Still, because Florida has received plenty of polling — and because SurveyUSA’s polls have been somewhat Democratic-leaning so far this cycle — the poll does not make too much difference in our forecast. Mr. Obama’s chances of winning Florida improved to 52 percent from 49 percent, according to our forecast model. If you’re determined to “call” each state, it technically flipped from red to blue. But if you look at the election probabilistically, as we do, these results are about the same.

Nevertheless, there had been earlier points when our model gave Mr. Obama no better than about a one-in-three chance of carrying Florida this November. As the results have closed there, it has moved up our chart of tipping-point states that are most likely to determine the election, and is now in an essential three-way tie with Pennsylvania and Virginia for second place on the list of the most important states. (All of these states rank below Ohio.) That means that as expensive as it is to run for office in Florida, it will, as usual, be a state that neither campaign can afford to take for granted.

Nate Silver is the founder and editor in chief of FiveThirtyEight. @natesilver538